This disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in one example described below, more particularly provides an expandable well screen with enhanced drainage when the screen is expanded downhole.
An expandable well screen can be used, for example, to support a wellbore wall and/or consolidate a gravel pack external to the well screen in production or injection operations. In one type of expandable well screen, a swellable material is used to displace filter sections of the well screen radially outward.
However, the swellable material can extrude onto an outer surface of a filter section, thereby reducing a surface area of the filter section available for fluid flow. In cased hole applications, the filter section may be pressed against a perforated casing or liner, so that only a surface area of the filter section exposed to perforations is available for fluid flow. Other problems may be experienced with expandable well screens, as well.
Therefore, it will be appreciated that improvements are continually needed in the arts of constructing and utilizing expandable well screens.